The purpose of these studies is to develop and utilize new arterial imaging, reconstruction and regional evaluation techniques to determine regional vascular reactivity in arterial segments with varying degrees of atherosclerosis and hypertension. The geometry of the arterial segments will be obtained from cross-sectional images using high-frequency echocardiographic techniques and position registration devices. Using computer-aided, 3-dimensional geometric reconstructions, hemodynamic measurements and finite element analysis, arterial material properties and shear stress will be assessed. Following the validation of the 3- dimensional reconstructions, segments will be reconstructed and evaluated in an animal model and in a normal patient group; and in patients with varying degrees of atherosclerosis and/or hypertension. Edge detection algorithms will be developed for rapid on-line 3-dimensional reconstruction of data sets. If morphologic predictors can be found that identify little or no vascular reactivity, then these segments may also be predicted to have the most benefit from interventions aimed at decreasing the atherosclerosis load. Our long-term goal is to use the combined imaging and reconstruction data along with the finite element approach to evaluate coronary and peripheral atherosclerosis and hypertension in a quantitative fashion, such that physiologic reactivity and results of pharmacologic and interventional techniques may be predicted with reasonable accuracy. The new techniques developed may allow other investigators to more quantitatively evaluate neural, humoral and structural alterations on the arterial bed.